Means for changing baffle pitch in a heat exchanger



`W. N. MCCURDY, JR., EI'AL lill-lull- |ll| Jan. 1, 1952 MEANS FOR CHANGING BAFFLE FITCH IN A HEAT EXCHAGER Filed Dec. 25, 1947 Janl, 1952 w. N. MCcURDY, JR., ETAL 2,581,121

MEANS FOR CHANGING BAFFLE FITCH IN A HEAT EXCHANGER Filed Dec. 23, 194'? 3 Sheets-Sheet 2 Fman Tuba 'SLOT-ran STRIP To SHEET Hom: @Loss EJAFr-Las iO 9 4 TUBES SLOT-ran 5mn: i@ pAlzabAFFLae-a E L1 G 2 ofobn. Untitleseg SYM/@fibers Jan' 1, 1952 w. N. MCCURDY, JR., ETAL 2,581,121

MEANS FOR CHANGING BAFFLE FITCH IN A HEAT EXCHANGER Filed Deo. 23, 1947 y 3 Sheets-Sheet 3 7`7'omajje C) C) 0 G Fearaj'le Alep/6er G G Q 0 0 Q O /l/ember 000000 3 000000/ 00000 A Patented Jan; 1, 1952 MEANS FOR CHANGING BAFFLE PITCH IN A HEAT EXCHANGER William N. McCurdy, Jr., Elizabeth, and John V. Whittlesey, Roselle, N. J., assignors to Standard Oil Development Com Delaware pany, a corporation of Application December 23, 1941, serial No. 793,428

2 Claims. 1

The present invention relates to an improved heat exchanger structure, and more particularly to an improvement in means for positioning and holding. baille elements therein in combination with means for protecting a heat exchanger tube bundle from accidental damage during insertion in or removal from an exchanger shell. A special feature of the invention is the provision of such means while also providing a means whereby the baille pitch, that is, the distance between individual ballles associated with the bundle may be altered without removing the tubes from their connection to either or both xed and iloating tube sheets.

In the conventional heat exchanger tube bundle. the exchanger tubes are -mounted in one or the other of the tube sheets, preferably the xed sheet, the tubes' being passed through perforations in the several baille members used. At the same time, tie rods are. inserted through certain of the perforations of the baille members, usually around the perimeter, passing through tubular spacer elements disposed between the baille members, which are of such length as has been determined as suitable for the spacing of such members, the tie rod being secured at one end to the fixed tube sheet and at the other to the last baille. member in the bundle. The tubes are then secured to the floating tube sheet.

In a tube bundle assembled in this fashion, it is frequently impossible to vary the pitch or spacing of the baille members without completely removing thefloating tube sheet or head, and also partially or fully withdrawing the tie rods for replacement of the spacer elements. Such an operation is extensive in nature and rather costly in time.

The present invention provides the means whereby baille pitch may be varied easily, and with a minimum expenditure of time. Such means may be more clearly understood from the following description when read in conjunction with the accompanying drawings, in which:

Fig. 1 is a perspective view of a heat exchanger with the shell and a portion of the tube bundle partly broken away to show the relationship of the several elements.

Fig. 2 is a vertical, longitudinal section through a tube` bundle assembled with slotted strip elements spacing and holding the baille members therein.

Fig. 3 is a perspective view of a baflle holding slotted strip element. A

Fig. 4 is a cross-sectional view along the line IV-IV of Fig. 1 showing the location and disposition of associated elements of the assembly.

Referring now to the several lgures with more particularity, similar elements of the structure being indicated by the same numerals as in Fig. l, the numeral l designates an exchanger shell in which is disposed an exchanger tube bundle. Primarily, the bundle is composed of xed and floating tube sheets 2 and 3 respectively secured therein, a plurality of tubes 4, a plurality of baille members 5, tie rods 6, spacer elements 1, and tube protector or cage rods 8 which serve to enclose the bundle in a protective cage of substantially rigid solid bars. These tube protectors or cage rods 8 are disposed in the peripheral space between the outer edge portions of the several baille members, and the periphery of the tube bundle, as shown, extending from a point of attachment on one tube sheet, through the several baille members, into unsecured, spaced relation to the other tube sheet. The rods 8 are intended to be of substantially the same diameter as the tubes, and disposed so as to conform with the arrangement pattern of the tubes in the bundle. It is also desirable that where possible, the positioningretainer members, such as rods 6 and elements 1, also conform to the tube arrangement in the tube bundle. The relative location of these elements is still more clearly illustrated by the showing of Fig. 4, which also shows the baille member construction by which a primary object of the invention is achieved. As indicated, each baille is provided with a plurality of slots 5a disposed in any desired spaced relation peripherally of the members 5. These slots are adapted to receive the baille retaining members, such as tie rods 8. By this means, the tie rods 6 may be lifted out of the respective slots 5a in bailles 5, by merely separating the rod from its connection to the last baille and to the xed tube sheet. When thus removed, the baille members may be shifted along the tubes and protector bars so as to alter their spacing in any desired fashion. After replacing or shifting the spacer elements 1 to suit the new spacing arrangement, or baille pitch, the tie rods may be replaced in the slots 5a and the assembly restored to service, Also cleaningA o'f the tube bundle exteriorly is facilitated by provision of the readily moveable tie rods and baille members described. In addition, yby providing for adjustment of baille location, in the manner set forth, it is possible to avoid localized erosion of tubes and the shell caused by higher velocity ow of liquid through the clearance space between the tubes and the baille perforations therefor, and be- 3 tween the peripheral edges of the baiiies and the shell. Tne cage rods I, in addition to providing substantial protection for the tube bundle, also serve to fill the peripheral space between the edges oi baiiles l and the periphery of the tube bundle, which space in the conventional tube bundle permits annular bypassing of the bundle between,l

bafiles by the preferential flow of liquid., gas or vapor through such space. The rods B by at least partially filling this annular space prevents partial channeling of ow through the exchanger between baffles.

In Figs. 2 and 3, a form of construction is illustrated, in which the means for positioning and holding the baille members i is a strip member I, slotted as at a in any desired fashion, but preferably so as to provide a maximum number of slots while avoiding excessive weakening of the strip. The strip 9 is inserted in the slots la of the baille member 5 so that the bottom or inner ends of slots 9a engage the same portion of slotsla, the depth of the respective slots being such that when so inserted the outer edge portions of the strips will coincide and be in thel same plane with the edge portion of the respective baille members. Each strip is provided with a lug portion 9b by which it is securedfto the iixed tube sheet. ,The other end of each strip member is held in place by means of engagement of the slotted portions 5a and 0a, and by a retaining ring III which encircles the bundle over the strips 9. Additional rings I0 may be utilized, and disposed at spaced intervals longitudinally of the bundle, if desired. When baille positioning and retaining strip members 9 are employed the annular, channeled ilow of iluid between bailles is also impeded,and this result is still further improved by the use of strip members l in con- Junction with the rods l.

The useful beneiit of the invention is obtained in this form of the invention by removing the ring members Il, and detaching the lugs 9b from the xed tube sheet 2, after which the strips 9 may be lifted out of slotted engagement with the l baille members 5. The baflles 5 may then be redisposed as desired and as permitted by the arrangement and spacing of slots 9a, and the assembly restored. Provision is made for maintaining areserve supply of baille members or for removal of baiiles from operative use by providing a series'of closely spaced slots adjacent the xed tube sheets. Where it is desired to remove bames from operation, they may be shiftedV to that end of the bundle, and held there, while the remaining bailles are redisposed. Where the 4 tie rods i and spacer elements 1 are utilized. the same result may be accomplished by use of spacer elements of suitable length between the outer stored baille and the next adjacent operating The invention has been described in conjunction with the accompanying drawings for the purpose of illustration, and it is not intended that the` invention shall be thus limited. but only by the appended claims.

What is elaimed is:

1. -In a heat exchanger. including an exchanger tube bundle having a :dxed tube sheet, a fioati'ig tube sheet. and a plurality of exchanger tubes connecting said sheets, adjustable baille means for said tube bundle, comprising a. plurality of perforated lateral bame members disposed in spaced relation longitudinally oi' said bundle with the exchanger tubes passing through said perforations, said members being slideable along said tubes, slotted portions in spaced relation peripheraliy of said members and aligned from member to member, a plurality of strip-like spacer-retainer elements each having lateral slotted portions extending into one edge thereof, said slotted portions adapted to engage the slotted portions of said baille members with the outer edge of said strip-like elements level with the edges of vsaid members, said element secured at one end to the ilxed tube sheet, and at least one annular retainer member `encircling the spacer-retainer elements, ,maintaining said elements in nxed relation to said baffle members.

2. An apparatus according to claim 1, in which the strip-like retainer element is provided with an additional series of slotted portions in the end secured'to said fixed 'tube sheet, which portions are adapted to receive baille members, while not in service in the tube bundle.

v A WILLIAM N. McCURDY, Ja.

y JQHN V. WHITI'LESEY.

semences cr'rnn/ l The following references are of record in th ille of this patent:

UNITE STATES PATENTS Number Name Date 1,764,200 Dean June 17, 1930 2,138,469 Barkley et al. Nov. 29, 1938 2,174,318 Ellis Sept. 26, 1939 2,183,160 Coulter et al. Dec. 12, 1939 2,269,619 Carpenter Jan. 13, 1942 2,496,301 Meixl T- Feb. '1, 1950 

